Secretory responses of the small gut to GI and other hormones will be investigated in dogs and rats. Extracts of intestinal mucosa will be used to stimulate secretion in both the intestine and the pancreas to determine whether gut extracts contain secretogogues other than pure cholecystokinin and secretin. The effects of denervation on the intestinal secretory respones will also be investigated. Volume, activity of several enzymes, DNA and osmolality will be determined.